Electromagnetic switch



1927. May 31 D. M. CBuss ELECTROMAGNETIG SWITCH Filed March 1l, 1924 Patented May 31, 1927.

UNITED STATES PATENT oFFicE.

DONALD M. BLISS, OF SYRACUSE, NEW YORK, ASSIGNOB.I TO SYRACUSE WASHING MACHINE CORPORATION, F SYRACUSE, NEW YORK, A CORPORATION OF DELA- WARE.

ELECTROMAGNETIC SWITCH.

Application led March 11, 1924. -Serial N o. 698,393.

This invention relates to electric switch 4ol the electro-magnetic, latch-trip type adapted to be used more particularly in con-A nection with clothes washing and wringing mechanisms when combined in the same machine and operated by an electric motor through the medium of clutches for stopping and starting either ot said mechanisms independently of the other` mechanism.

j, In machines of this character, the load upon the motor varies materially according to the volume ot clothes operated upon, and the main object ot' the present invention is to provide means connected in the motor circuit for automatically breaking said circuit and thereby preventing injury to the motor by either ot' said mechanisms in case the motor is overloaded.

I am aware that devices of this character o have heretofore been proposed to be used in connection with various motor-driven mechanisms to relieve the motor from overload, but'when used in connection with a com- I bined washing and wringing machine, it is desirable to place the switch where it may be most conveniently opened and closed at will when operating either mechanism, and one of the specic objects of the present 1nvention is to provide the switch with means (y whereby the circuit may be opened and closed at will when the operator is in position for attending the action of the washing or wringing irrespective of the action of the electro-magnet upon 'the switch.

Another object is to utilize the armature of the electro-magnet as a combined latch or' switch-holding member by permitting a compound rectilinear and transverse movement thereof, whereby one of the move-V i ments, as the rectilinear movement, serves to open and close the switch while the other transverse movement serves to lock the switch in its closed .position and to permit it to be released from its locked position.

i Another object is to provide a retracting spring for the armature arranged in such manner as to cause both movements.

Another 'object is to provide means'operable at will, for electing the rectilinear movement of the armature in one direction for closing the switch and an additional means operable atwill, for effecting a transverse movement of the armature to release it from its locking position independently of the electro-magnet,

A further object is to cause the electromagnet to be energized by excessive load upon the motor for releasing the armature from its locked position and thereby causing the circuit to be broken independently of the manually operated releasing means.

A still further object is to cause the movable switch member to engage and electrically connect the switch terminals with a laterally shifting -wiping elect to keep the contact surfaces clean and also to assure a more perfect contact.

Other objects and uses relating to specific parts of the device will be brought out in the following description.

In the drawings Figure l is a face view, partly in section, of a circuit-making and breaking device in which it is shown as adjusted and locked in its closed position, the cover being omitted and the motor circuit being shown diagrammatically.

Figure 2 is a similar face View, partly in section, in which the switch and its operating devices are shown in theirnormal open positions.

Figures 3 and 4 are sectional views taken respectively, on lines 3 3, and 4-4, Figure 2.

As illustrated, this device comprises a supporting base -lof insulating material for receiving and supporting the various operating parts and a suitable cover -2- which may vbe madevof metal andre- 4movably Asecured upon the base -l- 1n such manner that it may be removedwhenl necessary for inspection or repairs of the interior mechanism.

This mechanism comprises an electromagnet vwinding 3 wound upon a suitable core ,4- which in turn is supported upon a frame 5- on the supporting base -1- as shown more clearly in Figures 3 and 4, so that the core may extend parallel with the plane of the base at one side of the center thereof.-

The frame -`5- extends some distance beyond the inner end of the core -4- and is provided with opposite lugs or ears --5 at opposite sides of the axis of the core, sald lugs or ears being provided with rectilinearly alined apertures -6- and -6- for receiving and guiding a rectilinearly movable armature -7- which together with the openings -6- and -6- are' preferably angular or square in cross section to prevent turning of the armature in the guide openings and are also preferably disposed in the same plane as the core lof the electro-magnet so that the armature may extend across the inner end of the core in spaced relation thereto but within the field thereof.

The armature -7 is tree 'to slide endwise or rectilinearly in the guide openings -6v and -6- across the inner end of the core -lland is also free to move transversely toward and from said core for a purpose presently described, the opening being suii'iciently large to permit a limited transverse movement of the armature toward and from the core of the mag- On the end of the armature -7 adjacent the guide opening -6- and just at the outside of the corresponding lug or ear 5-, is provided an insulating block -8- upof electric-conducting material constituting the movable switch memberV to which the movements of the armature -7- are imparted.

This movable switch member -9- eX- tends beyond opposite sides of the insulating block as shown in Figure 3 and is adapted to make and break contact with a pair of spring terminals -10- which lare secured to the base -1- at opposite sides of the armature -7- and its insulating block -8- so as to project into the path of movement of the opposite ends of the connecting bar -.-9- as the armature -7- is moved endwise in one direction.

The switch member -9- and terminals -10- constitute an electric switch which is connected in series with the winding of the electro-magnet -3-- of a motor circuit -a including therein an electric motor v-A- as shown diagrammatically in Figure 1.

The motor circuit may be connected to any available source of power for operating the motor which in turn may transmit power to a combined washing and wringing mechanism of a clothes washing machine or may be used for other purposes in which it is desired to provide an automatic. circuit breaker of the character herein described.

The armature -7- serves the double purpose of a switch-operating member and a latch for releasably locking the movable switch member as -9- in its closed position in contact with the terminals -10-, and for this purpose is movable endwise transversely of the aXis of the electro-magnet and also axially of said magnet and is provided with a shoulder -11--l movable into and out of engagement with the lug -5- nearest the terminals l0- said lug forming a iXed detent for holding the arma- Lesaeco ture and movable switch member connected thereto in their closed positions.

The armature 7 and its switch member -9- are shifted to their closed positions by means oa bell crank lever -12- and a manually operated push 'button 13-, the lever -12 being pivoted at lto the supporting base -1- and having one end forked and engaged with a pin --l5- on the armature -7- and its other 7f end engaged with the inner end ot the push button--lwhich is movable in a suitable guide opening in a flange -l6 on the base lt A spring -18- has one end connected to one of the lugs -5- in a plane above the armature -Z-- and its other end connected to a bent arm -19- on said armature for retracting the latter, and the switch member -9-- carried thereby to their open 85 positions, the spring being arranged diagonally of the armature to effect the compound endwise and transverse movements of both the armature and switch member carried thereby.

The movement of the armature axially of the electro-magnet not only serves to engage the shoulder -11- of the armature with the adjacent lug or detent -5- to lock the switch in its closed position, but also to cause a lateral wiping movement of the contact member 9fwith the spring terminals -10- to keep the contacting faces bright and thereby to maintain a more efficient electrical connection when the switch is closed. luc

The locked armature latch` -7- and switch member -9- connected thereto may be released from their closed and locked positions either by the energizing of the electro-magnet -3- or through the medium 105 of a manually operated push button -20- which is movable in an opening in the flange -16- parallel with and adjacent to the push button 13-.

The inner end of the push button -20- 110 is provided with a flange -21- projecting across the adjacent end of the switch member -9- which, in turn, is disposed in the path of movement of the flange-Qlin all positions of adjustment of the switch member-Q- and particularly, when the latter is closed as shown in Figure l, in which case the inward pressure upon the push button -20- will engage the adjacent end of the switch member 9, thereby 12u forcing the same together with the armature latch -7- toward the electro-magnet 3- until its shoulder l1- is disengaged from the adjacent lug -5- whereupon the tension of the spring -18- will move the 125 armature and switch member endwise to open the switch and thereby break the motor circuit.

In starting the motor, the push button -13- is. forced inwardly for shifting the 130 armature -7- endwise against the action of the spring 1S- and thereby contacting the switch member -9- with the spring terminals land at.the same time permitting the shoulder 1lof the armature -,7- to be drawn into holding engagement with the stationary detent or lug This closing of the switch electrically connects the electro-magnet -3- in the motor circuit and causes the Operation of the motor and any mechanisms which may be driven thereby.

Thevwindin'g of the electro-magnet -3- is adjusted to allow the motor to be started under a light load without producing suticient magnet-ic attraction to release the armature from the detent -5-, but in case of overloading of the motor which would throw additional current into the electromagnet, the latter would attract the armature and thereby release it from the detent -5- and allow the spring 1S- to shit't the armature and its switch member -9- to an open-position to break the motor circuit.

On thel other hand, if the switch should be closed, and locked in its closed position7 as previously described and it should be desired to break the motor circuit at will, it is simply necessary to press the push button and switch member -9- engaged thereby inwardly, a sufficient distance to d1sengage the shoulder 1lfrom the detent -5- whereupon the spring -18- would immediately open the switch to break the motor circuit.

The operation of my invention will now be readily understood upon reference to the foregoing description and the yaccompanying drawing, but it is evident that various changes may be made in the detail construction and arrangement of the various parts without departing from the spirit of this invention.

l claim:

l. An electro-magnetic switch comprising a detent, an armature, .a switch having a movable member secured to the armature, means operable at will for moving the armature endwise in one direction for closing the switch, a spring for moving the armature in another direction into holding engagement with said detent when the switch is closed and for retracting said armature to open the switch when releasedv from the dctcnt, and an electro-magnet for releasing the armature from said detent.

2. ln an electro-magnetic switch, a detent, an armature having an endwise movement and a transverse movement, a switch meinber secured to the armature to move therewith, means operable at will for shifting the armature endwise in one direction to close the switch, a spring for moving the armature transversely in one direction for engaging the detent when the switch is closed, said spring serving also to retract the armature endwise in the opposite direction to open the switch when released from the det-ent, and an electro-magnet acting upon the armature when energized for releasing said armature from the detent and allowing said spring to return the armature and switch for opening said switch.

3. ln an electro-magnetic switch, a detent, an armature having an endwise movement and a transverse movement, a switch member secured to the armature to move therewith, means operable at will for shifting the armature endwise in one direction to close the switch, a spring for moving the armature transversely in one direct-ion for engaging the detent when the switch is closed, said sprin serving also to retract the armature en wise in the opposite direction to open the switch when released from the detent, and an electro-magnet acting upon the armature when energized for releasing said armature from the detent and allowing said spring to return the armature and switch for opening said switch, and means operable at will for releasing the armature from engagement with the detent independently of the electro-magnet.

lln witness whereof l have hereunto set my hand this sixth day of March, 1924.

DONALD M. BLISS. 

